The invention relates to a loading mechanism for a magnetic tape cassette apparatus with a lifting device and with a frame-shaped cassette holder which can be moved up and down by the lifting device. The cassette holder comprises an ejection slide which can be locked in a pushed-in position.
Loading mechanisms for the loading and unloading of magnetic tape cassettes in a magnetic tape cassette apparatus have already been known. In the case of such a device a cassette is frequently pushed from the front of the magnetic tape cassette apparatus into the cassette holder and then moved downwards vertically by the loading device in order to bring the cassette into the operating position. In the operating position the cassette placed in the apparatus is centered with the aid of centering pins. For cassette removal, the motor-driven lifting device lifts the cassette contained in the cassette holder out of the operating position into the eject position. When being moved downwards into the operating position the cassette must be locked in the cassette holder.
From DE-AS No. 2357445, to which U.S. Pat. No. 3,854,784 corresponds, a loading device for a magnetic tape cassette apparatus is known in which the locking takes place by means of a so-called "Shadow catch" mechanism, comprising a heart-shaped groove and a pin which scans this heart-shaped groove. When a cassette is pushed into the cassette holder by hand, the pin locks in the heart-shaped groove so that the cassette is locked in the pushed-in position. When pressed again, the pin comes back out of te heart-shaped groove and a spring moves an ejection slide with the cassette into the eject position. A disadvantage here is that, on each occasion, the cassette must be pushed again in order to eject it.
Another type of lifting device in a magnetic tape cassette apparatus is known from German Offenlegungsschrift No. 3229490. This lifting device is locked by a locking catch, when a cassette is lowered into the apparatus in the operating position. At the start of cassette ejection, a push pin first presses the magnetic head plate of the apparatus away in order to remove the magnetic head from the cassette. After this the cassette is lifted, whereupon the pushpin also swings away the locking catch during the further travel and then cancels the locking of the lifting device. The object of locking the lifting device in the lower position is therefore to prevent the cassette from being raised before the magnetic head has been completely removed from the cassette. This does not affect the locking of the cassette in the cassette holder, however.